Why not switch MSRV to 1.57?

[vabka]

1.57 released 7 month ago, so it can be accepted under

Tokio will keep a rolling MSRV (minimum supported rust version) policy of at least 6 months. When increasing the MSRV, the new Rust version must have been released at least six months ago. The current MSRV is 1.49.0.

PS: Why am i asking: hyperium/http#564

[Darksonn]

We only bump the MSRV if there's a sufficiently good reason to bump it.

[Pzixel]

Is using panic in const fns is a good sufficiently reason to bump it?

[Darksonn]

No. Having to do the array indexing trick is only a really minor inconvenience.

Besides, your link goes to a different library. Bumping Tokio's MSRV without even using it in Tokio really doesn't make any sense. The authors of http could bump their MSRV if they don't want to wait for Tokio. Alternatively, then they could also add build.rs version detection to use the panic! only on sufficiently new versions of rustc - that would give the benefits of improved error messages to most users of the library without bumping the MSRV.